Propeller-blade control



R. M. BUCHANAN.

PROPELLER BLADE CONTROL -APRL'lcATloN FILED MAB. 9. |921.

Patented Dec. 5, 1922.

1,438,093 PATENT oFFicE.

ROBERT M. BUCHANAN, OF BROOKSBURG, INDIANA.

PROPELLER-BLADE CONTROL.

Applicationiiled March 9, 1921. Serial No. 450,869.

To all whom. t may concern:

Be it known that I, ROBERT M. BU- CHANAN, a citizen ofthe United States, residing at Brooksburg, in the county of Jefferson and State of Indiana, have invented new and useful Improvements in Propeller- Blade Controls, of which the following is a specification.

This invention relates to improvements in means for changing the angular relation of the blades of propellers such as are used in aeroplanes and bolts, and the object of the invention is to provide means whereby the aviator or other operator may change the angular position of the propel- I ler blades with relation to their plane of rotation from that for maximum forward travel to a neutral one in which they are in the plane of rotation, and thence if desired to a position of like angularity on the opposite side of the plane of rotation, thereby providing a speed control for the object propelled and also means for changing its direction of travel Without slowing down or reversing the engine.

I accomplish the above, and other objects which will hereinafter appear, by the mechanism illustrated in the accompanying drawing, in which- Fig. 1 is a longitudinal central vertical section of my invention with the' propeller blades set for maximum forward travel. Fig. 2 is a similar view with the blades in reverse position for rearward maximum travel. Fig. 3 is a front elevation of the device as shown in Fig. 2 with the cap of the propeller hub removed to show the interior of the hub. Fig. 4 is a front elevation of the hub with the cap on. Fig. 5 is a side elevation of the lever for changing the blades and adjacent supporting box. Fig. 6 is a top plan view of the crank box with the top removed and Fig. 7 is an end view of one of the. propeller blades showing the range of adjustment of the blade.

Like characters of reference indicate like parts in the several views of the drawing.

The drive'shaft 8 derives its power from any suitable engine and drivingly connects with a propeller shaft 9 in any suitable manner. A propeller hub 10 is mounted on shaft 9 and has motion of rotation with said shaft which is here shown as square in cross section to cause the hub to rotate with it and also t0 permit of a sliding longitudinal adjustment on said shaft. The

hub has a cylindrical extension 11 of reduced -diameter which has a bearing in the adjacent end of a box 12. The reduction 1n diameter forms a shoulder 13, land the end of the extension 11 within the box is increased in diameter forming a shoulder 14, between which shoulder and the end of the extension nel which forms `the seat for a yoke 15, preferably in two parts for assembly, united by bolts 16. This yoke has diametrically opposite t/runnions to pivotally engage pitmen 17 and 18, which connect the yoke with the cranks of a shaft 19, mounted in the box and near the opposite end thereof from extension 11. An end of the crank-shaft 19 terminating outside of the box has a hand-lever 20 by which the shaft is rocked thereby sliding the extension 1l, and the hub 10 of which it is a part, on shaft 9. The lever 2O has a dog operated by a spring-actuated lever 21, to engage one of a series of notches in a segmentA 22 and hold a given position of the lever 20, for reasons that will presently appear.

The hub 10 is hollow, and mounted in a fixed manner on the end of shaft 9, within the hollow interior ofthe hub, is a head 23 having a pair of parallel integral rackloars 24 and 25. The teeth of these rackbars engage with the teeth-of corresponding pinions 26 and 27, mounted on respective separate radial propeller-bladel stubs 28 and 29, of blades 30 and 31. The adjacent ends of the stubs will preferably be steadied by being seated in a block 33, as here shown, removably secured in the bore of the hub, and a cap 34 is bolted to the outer end of the hub to close access to the hollow interior. The cap has openings for the passage out of the racks 24 and 25 and for a pin in the end of the block 33. The tilting of yoke 15 is prevented by guides 37 on which the ends of the trunnions rest.

The box 12 is preferably closed by a removable plate 35 to retain a lubricant with which the box may be filled. The box will be relatively stationary and suitably supported by means not shown.

The operation of my invention is as follows: The blades of the propeller are initially assembled in proper relation to each other, that is, so when the plane of one blade is in the plane of rotation of the propeller both blades will be alike n it; and

is an annular chan# when the upper blade is in maximum angularity with the plane of rotation in forward travel of the machine the diametrically opposite blade will be likewise set. Assuming that the blades are in maximum angular position relative to the plane of rotation shown in Fig. 1, a movement to the rear oflever 2() will draw the hub 10 towards box 12 carrying pinions 26 and 27 with it in contact with their racks and thereby rotating the blades from maximum angularity to zero, when their planes coincide with the plane of rotation of the blades, and thence to the opposite angular-ity or reverse, which will move the machine backwards.

The propelling action will vary at every different position and a given position will be held by engagement of dog on lever 20 with a corresponding notch of segment 22.

Various modifications will suggest themselves to those skilled in the art, as for example, moving the rack-bars while the pinions and hub remain relatively fixed (not shown), and Ido not desire to be limited any more than isy required by theappended claims, and having thus fully described my invention, what I claim as new and l"wish to secure by Letters Patent of the United States, is-

1. A propeller shaft, a hollow hub mounted thereon, a removable hub cap, a block removably secured in said hub to said cap, a plurality of propeller blade stubs entering the hub radially thereof and having their ends seated in the block, .a pinion in the hub on each stub and a propeller blade on each stub, in combination with means ifisaoee comprising rack-.bars engaging the pinions for changing the angular relation of the blades to the plane of rotation of the propeller without stopping the rotation of the propeller.

2. A manually rocked shaft having cranks, a rotating shaft having a yoke-seat, a yoke in said seat having trunnions, pitmen connecting the trunnions with said crank, a hollow hub on the shaft having motion of rotation therewith and longitudinally sliding adjustment thereon, a head in the hub having rack-bars said head being fixed on the rotating shaft, a cap closing the hollow hub, a block separate from but located in the hub, block holding means supported by the cap, shaft stubs journaled in the hub and block radially ofthe hub, and propeller blades mounted on the stubs', said stubs having pinions engaging with the rack-bars.

3. A manually rocked shaft having cranks, a rotating shaft having a yoke-seat. a yoke in said seat having trunnions, pitman rods connecting the trunnions with said crank, a hollow hub on the shaft having motion of rotation therewith and longitudinally sliding adjustment thereon, a head on the hub having rack-barssaid head being fixed on the rotating shaft, propeller blades mounted on the hub and having pinions engaging with the rack-bars, a remo-vable block inthe hub and means for holding the block removable while in use, said propeller blades having shafts which are seated in the block.

Signed at Brooksburg, lindiana, this the 1st day of March, 1921.

ROBT. M. BUCHANAN. 

